Straightenting machine for straightening elongated bodies

ABSTRACT

A straightening machine for straightening an elongated body, such as a pipe, a composite pipe or a rod, including a machine frame ( 2,3 ) and a number of radially adjustable straightening rolls ( 32 - 35 ) mounted alongside a straightening channel ( 20 ) and offset or alternatingly on supports ( 24 - 27 ) in the direction of the longitudinal axis ( 10 ) and in a circumferential direction. The machine allows an adjustment to different diameters or outer contours of the elongated bodies, and for this purpose, the supports ( 24 - 27 ) are guided in at least one displacement plate ( 8, 9 ) about the longitudinal axis ( 10 ) of the straightening channel ( 20 ). The displacement plate ( 8, 9 ) includes first adjustment elements ( 36 - 39 ) which engage second adjustment elements ( 40, 41 ) on the supports ( 24 - 27 ) such that the radial spacing of the straightening rolls ( 32 - 35 ) relative to the longitudinal axis ( 10 ) is changed by turning the displacement plate ( 8, 9 ).

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of international patent application no. PCT/EP00/09570, filed Sep. 29, 2000, designating the United States of America, the entire disclosure of which is incorporated herein by reference. Priority is claimed based on Federal Republic of Germany patent application no. DE 299 17 408.5, filed Oct. 2, 1999.

BACKGROUND OF THE INVENTION

[0002] The invention relates to a bending machine for straightening elongated bodies, especially pipes, plastic composite pipes, rods, or profiles.

[0003] A bending machine of this type is known from German Patent Application no DE 197 50 616, which is designed to straighten rolled profiles. This bending machine comprises a number of straightening rollers that form a straightening channel and act on the surface of the rolled profile or elongated body that is fed into the straightening channel. In addition, an adjustment element is provided that has an adjustable runout roller to guide the straightened rolled profile, and that is adjustable by means of a sensor and an adjustment regulator. The bending machine is a complex, stationary piece of equipment used in rolling mills, and is not particularly suitable for mobile applications at work sites, machine shops, or workshops.

[0004] Furthermore, a bending machine for pipes, profiles, and the like is known from German Patent no. DE 235 34 428, which has a design based on a linear, straight alignment and having bends and curves with small bending radii. This bending machine comprises on the one hand feed rollers between which the pipe or similar body is fed in a specified first direction, and on the other hand bending rollers on which slides are arranged that can be moved at right angles to the first direction. Although the bending machine constitutes a compact, portable unit, the pipes, profiles, and similar bodies that are prepared in a curved or bent state cannot be straightened without further processing. The feed rollers are diametrically arranged in pairs to accommodate the diameter or outer contour of the elongated body, so that for other diameters or outer contours, the rollers must be replaced by other rollers of appropriate design. This is extremely time consuming, and is not suitable for the austere operating conditions at a work site. Moreover, sets of various rollers must be kept on hand. A further significant disadvantage is that the rollers are externally accessible, resulting in potential safety hazards.

[0005] In the current art, elongated bodies such as pipes, rods, or profiles are often processed on rollers whose diameters typically range from 1 to 2 m, corresponding to the flexibility of the elongated body. After the elongated body is rolled out, it has a corresponding bend radius such that the body generally cannot be laid out perfectly straight. Even slight curvatures are undesirable, particularly for installation techniques such as laying water pipes, especially surface installations, but also for underground installations as well. Similar problems arise in the laying or installation of rods or profiles, such as for cable ducts, sheathing, scaffolding, and the like.

SUMMARY OF THE INVENTION

[0006] It is an object of the invention to provide a bending machine of the aforementioned type which can be constructed at reasonable cost.

[0007] Another object of the invention is to provide a bending machine which allows adjustments to be easily made for different diameters or outer contours of an elongated body which is to be straightened.

[0008] A further object of the invention is to provide a bending machine which avoids the need for special modifications.

[0009] It is also an object of the invention to provide an easily handled bending machine which has low material and production costs.

[0010] These and other objects are achieved in accordance with the present invention by providing a bending machine for straightening an elongated body, comprising a machine frame and a plurality of straightening rollers disposed in the frame, the rollers being mounted on supports along a straightening channel displaced along and circumferentially around an axis of the straightening channel, and the straightening rollers being radially adjustable such that the elongated body can be moved through the straightening channel, wherein the supports are guided in at least one displacement plate that can be rotated about the longitudinal axis of the straightening channel; the displacement plate comprising first adjustment elements which engage second adjustment elements on the supports, and wherein the radial distance of the radially adjustable straightening rollers relative to the longitudinal axis can be changed by rotating the displacement plate.

[0011] The bending machine according to the invention is characterized by a simple construction that allows adjustments to be easily made for different diameters or outer contours of the elongated body to be straightened. A number of straightening rollers are mounted along a straightening channel on radially displaceable supports, which together may be adjusted by a displacement plate. It is advantageous for the supports to be diametrically opposed in pairs, the supports having at least two diametrically opposed straightening rollers. In a special embodiment, four supports are offset by at least approximately 90° to one another in relation to the straightening channel or the longitudinal axis, whereby each respective pair of diametrically opposed supports has at least one pair of diametrically arranged rollers. In a special embodiment, the supports are mounted in the machine frame so as to be radially displaceable, so that by means of the displacement plate the radial position of the supports, and thus of the respective straightening rollers, can be specified with respect to the longitudinal axis by rotating the displacement plate. Alternatively, the supports may be pivotably mounted about a fixed pivot bearing, or may also be mounted by means of the free bearing formed by the displacement plate so as to be radially adjustable in the required manner.

[0012] The displacement plate and the respective supports have mutually corresponding guide elements. In particular, the guide elements may comprise a shaft and a corresponding guide groove. The shaft may be associated with the support and the guide groove with the displacement plate, or vice versa. The displacement plate is rotatably mounted in the machine frame about the longitudinal axis of the straightening channel, such that the radial adjustment of the supports, and thus of the straightening rollers adjoining the straightening channel, is determined in accordance with the rotational position of the displacement plate. The bending machine is a compact, preferably portable unit having a total weight of a few kilograms, and it can be easily carried by one person to the desired location of use.

[0013] It is advantageous to mount two displacement plates, one on each axial end of the supports, to assure a secure mounting of the supports along with the straightening rollers in the machine frame. An adjustment handle is advantageously connected to the one or two displacement plates, thereby facilitating synchronous rotation of the displacement plate(s) about the longitudinal axis. Furthermore, adjustment marks are assigned to at least one plate in such a way that the position at the time, and ultimately the adjusted distance of the straightening rollers relative to the longitudinal axis and thus to the adjusted pipe diameter, may be easily determined by an operator.

[0014] The machine frame, which advantageously has a guide plate on each end, has an opening at each end for inserting and withdrawing the elongated body, with the straightening channel and the straightening rollers being situated between the openings. The straightening rollers are preferably mounted radially inside each support, thus protecting against undesired access and eliminating safety hazards for the operator.

[0015] In one specific embodiment of the invention, the bending machine includes a cutting device for cutting the elongated body to a desired length. In this manner primarily pipes, especially plastic composite pipes, may be cut to the required length for further processing. By integrating the cutting device according to the invention into the bending machine, the bending machine acquires a dual function, thus allowing elongated bodies to be straightened and cut within a short time.

[0016] Specific embodiments and refinements of the invention are described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The invention will be explained in further detail with reference to illustrative preferred embodiments shown in the accompanying drawings, it being understood that the embodiments depicted are merely examples and that the invention is not limited thereto. In the drawings:

[0018]FIG. 1 is a perspective view of a bending machine according to the invention;

[0019]FIG. 2 is a longitudinal section through the bending machine along sectional plane II of FIG. 1;

[0020]FIG. 3 is a partial view in the viewing direction III of FIG. 2;

[0021]FIG. 4 is a perspective view in the sectional plane II according to FIG. 1, and

[0022]FIG. 5 is a view of a straightening roller.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0023]FIG. 1 shows in perspective view the bending machine, comprising a machine frame having two guide plates 2, 3 that are connected to one another by rods 4. Corresponding to rod 4 on the right in the drawing, an additional rod is present in the region of the lower ends 6 of the guide plates 2, 3. Two displacement plates 8, 9 are mounted on the mutually facing inner surfaces of the guide plates 2, 3 so as to be rotatable about the longitudinal axis 10. An adjustment handle 12, provided for rotation of the displacement plates 8, 9, is affixed to radially outwardly projecting cams 14, 15 on the displacement plates 8, 9.

[0024] The guide plate 2 has an adjustment mark 16 which is correlated with markings on the outer surface of the displacement plate 8. The markings 18 relate to different diameters of a straightening channel 20 which is coaxial to the longitudinal axis 10 and which can be preset by means of straightening rollers, to be described hereinafter. Corresponding to the straightening channel, whose diameter is adjusted by rotating the displacement plates 8, 9 about the longitudinal axis 10, elongated bodies, especially pipes or plastic composite pipes, of different diameters can be straightened using the bending machine. The marking 18 corresponding to the respective diameter is aligned with the adjustment mark 16 by rotating the displacement plates 8, 9 in the direction of the arrow 22.

[0025] Four supports are mounted between the displacement plates 8, 9 essentially parallel to the longitudinal axis 10. The two supports 24, 25 visible in the drawing are mounted so as to offset one another by 90° in relation to the longitudinal axis 10. A third support is mounted diametrically opposite and below the upper support 24 as shown in the drawing. A fourth support is mounted diametrically opposite the support 25.

[0026] Supports 24, 25, and correspondingly the other two supports, have bearing blocks 28, 29 for the aforementioned straightening rollers, with only the one straightening roller 32 of the rear support diametrically opposite the front support 25 being visible in the drawing.

[0027] The displacement plates 8, 9 comprise first adjustment elements which correspond to second adjustment elements of the respective support 24, 25. According to the drawing, the first adjustment element 36 is constructed as a groove that is spiral-shaped with respect to the longitudinal axis 10, within which groove the second adjustment element of support 24 in the form of a shaft, not visible here, engages. The adjustment elements, i.e., the spiral-shaped groove 36 and the shaft engaging in groove 36, are designed in such a way that rotation of the displacement plates 8, 9 corresponding to the arrow 22 displaces the support 24 radially outwardly in the direction of the arrow 23. It is understood that rotation in the direction opposite to the arrow 22 displaces the support 24 radially inwardly.

[0028] In addition, it is noted that the adjustment elements are designed to correspond to the other axial end of the support 24 and the displacement plate 8 mounted there. Furthermore, the three other supports can be adjusted radially in an analogous manner by means of corresponding adjustment elements. It is essential that all supports be synchronously radially displaced outwardly or radially displaced inwardly by rotation of the two displacement plates 8, 9 that are connected by the adjustment handle 12, so that the straightening rollers of all the supports have matching radial distances relative to the longitudinal axis 10, corresponding to the rotational position of the displacement plates 8, 9.

[0029] The guide plate 2 has an opening 42 having a diameter which is equal to or greater than the outer diameter of the body or pipe, rod, or the like to be straightened by the bending machine. The guide plate 3 on the opposite end also has a corresponding opening that is coaxial to the longitudinal axis 10. The diameters (or for profiles or rods with different outer contours, the widths) of these openings are significantly larger than the maximum diameters or the maximum widths of the outer contours, thus reliably avoiding safety hazards for the operator when inserting a pipe or other elongated body into the opening. The fact that the straightening rollers are shielded by the radially outwardly mounted supports also avoids hazards for the operator.

[0030] The guide plate 2 on its inner side facing toward supports 24, 25 has four radial guide grooves 46 through 49 in which shafts of the respective support engage. Each support advantageously has two radially spaced shafts, and the width of the guide grooves 46 through 49 is advantageously substantially equal to the diameter of these shafts. The radial length of the guide grooves 46 through 49 is matched to the radial displacement path of the supports, taking the shaft diameters into account. Functionally reliable mounting and radial guiding of the supports in the machine frame are thus assured.

[0031] Instead of the two essentially cylindrical shafts provided for each support, each support may have an elongated guide body, similar to a feather key, which engages with the associated guide groove, the radial length of which is specified in accordance with the radial displacement path of the support. It should be noted that not only the front guide plate 2 according to the drawing, but also the other guide plate 3 likewise has corresponding guide grooves.

[0032] Alternatively, the radial guide elements according to the invention can be designed in such a way that shafts are mounted on the guide plates 2, 3 and the supports have corresponding radial guide grooves. In addition, the guide plate 3 has an axial adjustment pin 58 which will be further explained hereinafter.

[0033] Although the arrangement of four supports, mounted so as to be offset from one another by 90° relative to the longitudinal axis, has proven to be particularly advantageous, a different number of supports may be provided within the scope of the invention. It is preferable to mount at least three supports. According to the invention, the supports are symmetrically mounted about the longitudinal axis so as to offset one another, each by the same angle.

[0034]FIG. 2 shows a section through the bending machine in an axial sectional plane, with the two axially spaced, outer guide plates 2, 3 and the rear connecting rod 5 of the machine frame. According to the invention, the guide plates 2, 3 have support or guide surfaces, coaxial to the longitudinal axis 10, for the associated displacement plates 8, 9. In the region of the mutually facing inner surfaces of the guide plates 2, 3 are preferably provided axial projections 44, 45, having outer surfaces coaxial to the longitudinal axis 10, upon which the two displacement plates 8, 9 are rotatably mounted.

[0035] The aforementioned second adjustment elements, in the form of the aforementioned axially aligned shafts 40, 41 of the respective upper or lower support 24 or 26 shown in the drawing, engage with the first adjustment elements 36, 38 of the displacement plates 8, 9, with the adjustment elements being designed as spiral grooves. The displacement plates 2, 3 also contain the radial guide grooves 46, 47 in which the second adjustment elements or shafts 40, 41 likewise engage.

[0036] The shafts 40, 41 are components of rods 50, 51, whose respective axial lengths are greater than the axial lengths of the supports 24, 26. The respective supports 24, 26 and correspondingly, the supports situated behind or in front of the plane of projection, are axially penetrated by two of the rods 50, 51. The radial guide grooves 46, 48 act to radially guide and prevent rotation of the respective supports during rotation of the displacement plates 8,9 to adjust the straightening rollers 32, 34, 35 of the respective support.

[0037] It can be seen that the supports each have four axially spaced straightening rollers. The different straightening rollers of the individual supports are axially offset from one another. For each support, the respective straightening rollers are arranged equidistantly. The support 27 situated behind the plane of projection has two bearing blocks 30, 31 for rotatably mounting the straightening roller 35 situated between the bearing blocks 30, 31. It is understood that the straightening rollers for the three other supports are arranged and mounted in a corresponding fashion.

[0038] The bending machine further comprises a cutting device 52 having cutting rollers 54, 55. The cutting rollers may be adjusted in the radial direction by the cutting device 52, so that the distance between the cutting rollers may be reduced, if needed, to cut off the body or pipe present in the bending machine. For this purpose the cutting device 52 has a spindle, indicated by a dotted line 56, which is mounted outside the straightening channel and by which the cutting rollers 54, 55 may be radially adjusted as desired. Both of the cutting rollers 54, 55 are adjusted during the straightening process so as not to contact the outer surface of the body or pipe. Cutting is performed by adjusting the cutting rollers 54, 55 to the outer surface of the body or pipe, successively readjusting to reduce the radial distance from the cutting rollers 54, 55, and rotating the body or pipe about the longitudinal axis 10.

[0039]FIG. 3 shows the bending machine in a partial axial view, namely, in the sectional plane III according to FIG. 2. The displacement plate 9 rotatably mounted on the axial projection 45 has four spiral-shaped grooves 36 through 39 in or through which the radially spaced shafts 40, 41 of the respective supports 24 through 27 engage. The straightening rollers 32 through 35 enclosing the straightening channel 20 may be easily identified here.

[0040] The guide plate situated in front of the plane of projection has at least one adjustment pin 58 which extends into the region of the displacement plate 9. The displacement plate 9 has an adjustment groove 60 extending in the circumferential direction which has locking positions 62 constructed as indentations. Rotating the displacement plate 9 in the direction of the arrow 22 causes the adjustment pin 58 to move into the adjustment groove 60.

[0041] The adjustment groove 60 and its locking positions 62 are preferably designed in such a way that during rotation of the displacement plate 9, specified adjustment positions of the displacement plate are occupied corresponding to specified pipe diameters. The adjustment grooves and locking positions are formed and constructed, for example, so that during rotation of the displacement plate 9 the supports 24 through 27 are radially displaced in a specified adjustment range in preset increments, for example, by 16 to 32 mm for pipe diameters, and are set in a fixed manner.

[0042] It is advantageous to provide four such adjustment pins 58 with corresponding adjustment grooves, distributed over the circumference. For simplicity, only one adjustment groove 60 is shown here. Additionally or alternatively, at least one of the spiral-shaped grooves 36 through 39 may have, in the region of its lateral surfaces, corresponding notches 64, 65 as locking positions in order to specify defined rotational angle positions of the displacement plate 9, and thus the defined adjustments of the straightening rollers 32 through 35, so that the shafts 40, 41 engage in the angular positions of the displacement plate 9 which are thus specified.

[0043]FIG. 4 shows in an axial sectional plane a perspective view of the bending machine comprising two guide plates 2, 3 having radial guide grooves 46, 48 for the shafts 40, 41 for the two supports 24, 26, shown here in a diametrically opposed arrangement. The four equidistant straightening rollers 35 of the support 27 and the associated bearing blocks 30, 31 for the respective straightening roller 35 may be easily identified here.

[0044] The rods 50, 51 engage at their ends, which are formed by the shafts 40, 41, in the radial guide grooves 46. The supports 24, 26 are depicted in the radially adjustable position that is nearest to the longitudinal axis. Corresponding to the free section of the guide groove 46 situated radially above the rod 50 or the shaft 40 thereof, the support 24 and correspondingly the other supports as well may be displaced outwardly or inwardly in the radial direction as indicated by the arrow 23, by rotating the displacement plates 8, 9.

[0045]FIG. 5 shows a view of the straightening roller 32, the outer surface 70 of which has a specified curvature that allows use for different diameters of the pipes to be straightened. To this end, the outer surface 70 is adapted, in the center 72 of the straightening roller 32, to the radius of the smallest pipe diameter. At the axial end regions of the roller 32, the roller diameter is increased out to the edge region 74 to accommodate the largest possible pipe diameter.

[0046] The following procedure is performed to straighten a body or pipe. First, the bending machine is adjusted to the desired diameter by rotating the displacement plates 8, 9 by means of the adjustment handle 12 until the marking 18 associated with the desired diameter matches up with the adjustment mark 16, as shown in FIG. 1. In addition, the adjusting pin 58 engages in the associated locking position 62, and/or the shaft(s) 40, 41 engage with the respective notches 64, 65 of the spiral-shaped groove 36, as described above with reference to FIG. 3. The pipe which is unrolled or otherwise bent by a roller is pushed through the opening 42 into the straightening channel and is then manually pushed out until it exits through the other opening 43 in a straightened state.

[0047] The foregoing description and examples have been set forth merely to illustrate the invention and are not intended to be limiting. Since modifications of the described embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed broadly to include all variations falling within the scope of the appended claims and equivalents thereof. 

What is claimed is:
 1. A bending machine for straightening an elongated body, comprising a machine frame and a plurality of straightening rollers disposed in said frame, said rollers being mounted on supports along a straightening channel displaced along and circumferentially around an axis of said straightening channel, and said straightening rollers being radially adjustable such that the elongated body can be moved through the straightening channel, wherein said supports are guided in at least one displacement plate that can be rotated about the longitudinal axis of the straightening channel; said displacement plate comprising first adjustment elements which engage second adjustment elements on the supports, and wherein the radial distance of the radially adjustable straightening rollers relative to the longitudinal axis can be changed by rotating the displacement plate.
 2. A bending machine according to claim 1, wherein the first adjustment elements are constructed as spiral grooves and the second adjustment elements are constructed as shafts that engage the spiral grooves.
 3. A bending machine according to claim 1, wherein the first adjustment elements are constructed as shafts, and the second adjustment elements are constructed as spiral grooves in which said shafts engage.
 4. A bending machine according to claim 1, wherein the machine frame comprises openings through which the body to be straightened is passed.
 5. A bending machine according to claim 1, wherein the machine frame comprises two guide plates spaced an axial distance from one another.
 6. A bending machine according to claim 5, wherein said guide plates comprise openings through which the body to be straightened is passed.
 7. A bending machine according to claim 1, wherein the supports are axially mounted between the two axially spaced displacement plates.
 8. A bending machine according to claim 1, wherein the displacement plates are axially mounted between two guide plates arranged at a distance from one another on the machine frame.
 9. A bending machine according to claim 1, wherein the displacement plates are connected to one another by an adjustment handle.
 10. A bending machine according to claim 1, wherein the machine frame has at least one axial projection having an outer surface upon which the displacement plate is rotatably mounted.
 11. A bending machine according to claim 5, wherein the guide plates have at least one axial projection having an outer surface upon which the displacement plate is rotatably mounted.
 12. A bending machine according to claim 1, wherein the machine frame has at least one guide surface coaxial to the longitudinal axis for the displacement plate.
 13. A bending machine according to claim 5, wherein the guide plates have support surfaces coaxial to the longitudinal axis for the displacement plate.
 14. A bending machine according to claim 1, wherein the machine frame and/or the guide plates (2, 3) have essentially radially aligned guide grooves (46-49) for radially guiding the supports.
 15. A bending machine according to claim 1, wherein guide bodies on respective supports engage the guide grooves.
 16. A bending machine according to claim 15, wherein the guide bodies are constructed as essentially axially aligned shafts.
 17. A bending machine according to claim 1, wherein each of the respective supports is axially penetrated by at least one rod.
 18. A bending machine according to claim 17, wherein the second adjusting elements are formed by free ends of the rods projecting from the supports and engage the spiral groove of the first adjusting elements.
 19. A bending machine according to claim 17, wherein the rods have free ends which engage radial guide grooves in the guide plate associated with the respective support.
 20. A bending machine according to claim 1, further comprising a cutting device comprising at least two cutting rollers.
 21. A bending machine according to claim 20, wherein the cutting device including the cutting rollers is mounted on two diametrically opposed supports.
 22. A bending machine according to claim 1, wherein the straightening rollers are respectively arranged between two bearing blocks of the associated support and are rotatably mounted. 